U1280

DTC Troubleshooting: U1280

DTC U1280: Communication Bus Line Error (BUS-OFF)

1. Clear the DTCs with the HDS.

2. Turn the ignition switch to LOCK (0) and then back to ON (II).

3. Wait for 6 seconds or more.

4. Check for DTCs with the HDS.

Is DTC U1280 indicated?
YES - Go to step 5.

NO - Intermittent failure, the system is OK at this time. Check for loose or poor connections, or worn/shorted wires. If the connections are good, check the battery condition Testing and Inspection and the charging system.


5. Turn the ignition switch to LOCK (0).

6. Disconnect the appropriate connector at each control unit in the table one at a time. Clear the DTC, then recheck for DTCs after each unit is disconnected.





*1: With premium audio system

*2: With climate control system

*3: USA models with climate control system

Is DTC U1280 indicated with each individual unit disconnected?
YES - Go to step 7.

NO - Go to the input test for the control unit that was disconnected when DTC U1280 did not reset and do all power and ground input tests. If the tests prove OK, replace that unit.

- Passenger's MICU input test. Multiplex Integrated Control System MICU Input Test

- Gauge control module input test. Gauge Control Module Input Test

- Door multiplex control unit input test. Power Window Master Switch Input Test

- Climate control unit input test. Climate Control Power and Ground Circuit Troubleshooting (With Climate Control)

- Immobilizer-keyless control unit input test. Immobilizer-Keyless Control Unit Input Test

- HandsFreeLink control unit input test. HandsFreeLink System Description (With HandsFreeLink)



7. Turn the ignition switch to LOCK (0).

8. Disconnect each control unit connector in the table.





*1: With premium audio system

*2: With climate control system

*3: USA models with climate control system

9. Disconnect driver's under-dash fuse/relay box connector P (20P).

10. Check for continuity between driver's under-dash fuse/relay box connector P (20P) terminals No. 5 and No. 6.

Is there continuity?
YES - Repair short between the B-CAN wires.

NO - Go to step 11.






11. Check for continuity between body ground and the driver's under-dash fuse/relay box connector P (20P) terminals No. 5 and No. 6 individually.

Is there continuity?
YES - Repair a short to ground in the wire.

NO - Go to step 12.






12. Turn the ignition switch ON (II).

13. Measure the voltage between body ground and the driver's under-dash fuse/relay box connector P (20P) terminals No. 5 and No. 6 individually.

Is there voltage?
YES - Repair a short to power in the wire.

NO - Faulty driver's MICU, replace the driver's under-dash fuse/relay box. Drivers Under-Dash Fuse/Relay Box (MICU) Removal/Installation